KURT_PARTR
ID KURT_PARTR Reviewed; 63 AA.
AC P58910;
DT 26-JUL-2002, integrated into UniProtKB/Swiss-Prot.
DT 26-JUL-2002, sequence version 1.
DT 03-AUG-2022, entry version 78.
DE RecName: Full=Kurtoxin;
DE Short=Ktx;
OS Parabuthus transvaalicus (South African fattail scorpion).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC Scorpiones; Buthida; Buthoidea; Buthidae; Parabuthus.
OX NCBI_TaxID=170972;
RN [1]
RP PROTEIN SEQUENCE, MASS SPECTROMETRY, AND FUNCTION.
RC TISSUE=Venom;
RX PubMed=10196582; DOI=10.1038/3669;
RA Chuang R.S.-I., Jaffe H., Cribbs L., Perez-Reyes E., Swartz K.J.;
RT "Inhibition of T-type voltage-gated calcium channels by a new scorpion
RT toxin.";
RL Nat. Neurosci. 1:668-674(1998).
RN [2]
RP FUNCTION ON CALCIUM CHANNELS.
RX PubMed=11896142; DOI=10.1523/jneurosci.22-06-02023.2002;
RA Sidach S.S., Mintz I.M.;
RT "Kurtoxin, a gating modifier of neuronal high- and low-threshold Ca
RT channels.";
RL J. Neurosci. 22:2023-2034(2002).
RN [3]
RP STRUCTURE BY NMR, AND DISULFIDE BONDS.
RA Lee C.W., Min H.J., Cho E.M., Kohno T., Eu Y.J., Kim J.I.;
RT "Solution structure of kurtoxin.";
RL Submitted (JUN-2005) to the PDB data bank.
CC -!- FUNCTION: Alpha toxins bind voltage-independently at site-3 of sodium
CC channels and inhibit the inactivation of the activated channels,
CC thereby blocking neuronal transmission. This toxin acts on
CC Nav1.2/SCN2A. Also binds to Cav3.1/CACNA1G and Cav3.2/CACNA1H T-type
CC calcium channels with high affinity and inhibits the channels by
CC modifying voltage-dependent gating. Another study (PubMed:11896142)
CC shows that it also targets neuronal high-threshold calcium channels,
CC including P-type, N-type, and L-type calcium channels (Cav), and others
CC that still are unidentified pharmacologically.
CC {ECO:0000269|PubMed:10196582, ECO:0000269|PubMed:11896142}.
CC -!- SUBCELLULAR LOCATION: Secreted.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to
CC antiparallel beta-sheets by disulfide bonds (CS-alpha/beta).
CC {ECO:0000305}.
CC -!- MASS SPECTROMETRY: Mass=7386.1; Method=Electrospray;
CC Evidence={ECO:0000269|PubMed:10196582};
CC -!- MISCELLANEOUS: This toxin does not affect Cav1.2/CACNA1C,
CC Cav2.1/CACNA1A, Cav2.2/CACNA1B, and Cav2.3/CACNA1E calcium channels.
CC {ECO:0000305|PubMed:10196582}.
CC -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC Sodium channel inhibitor family. Alpha subfamily. {ECO:0000305}.
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DR PDB; 1T1T; NMR; -; A=1-63.
DR PDBsum; 1T1T; -.
DR AlphaFoldDB; P58910; -.
DR SMR; P58910; -.
DR EvolutionaryTrace; P58910; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0005246; F:calcium channel regulator activity; IEA:UniProtKB-KW.
DR GO; GO:0019871; F:sodium channel inhibitor activity; IEA:InterPro.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR GO; GO:0006952; P:defense response; IEA:InterPro.
DR CDD; cd00107; Knot1; 1.
DR Gene3D; 3.30.30.10; -; 1.
DR InterPro; IPR044062; LCN-type_CS_alpha_beta_dom.
DR InterPro; IPR003614; Scorpion_toxin-like.
DR InterPro; IPR036574; Scorpion_toxin-like_sf.
DR InterPro; IPR018218; Scorpion_toxinL.
DR InterPro; IPR002061; Scorpion_toxinL/defensin.
DR Pfam; PF00537; Toxin_3; 1.
DR PRINTS; PR00285; SCORPNTOXIN.
DR SMART; SM00505; Knot1; 1.
DR SUPFAM; SSF57095; SSF57095; 1.
DR PROSITE; PS51863; LCN_CSAB; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Calcium channel impairing toxin; Direct protein sequencing;
KW Disulfide bond; Ion channel impairing toxin; Neurotoxin; Secreted; Toxin;
KW Voltage-gated calcium channel impairing toxin;
KW Voltage-gated sodium channel impairing toxin.
FT CHAIN 1..63
FT /note="Kurtoxin"
FT /id="PRO_0000066792"
FT DOMAIN 2..62
FT /note="LCN-type CS-alpha/beta"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 12..61
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210,
FT ECO:0000269|Ref.3, ECO:0000312|PDB:1T1T"
FT DISULFID 16..37
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210,
FT ECO:0000269|Ref.3, ECO:0000312|PDB:1T1T"
FT DISULFID 23..44
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210,
FT ECO:0000269|Ref.3, ECO:0000312|PDB:1T1T"
FT DISULFID 27..46
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210,
FT ECO:0000269|Ref.3, ECO:0000312|PDB:1T1T"
FT STRAND 2..4
FT /evidence="ECO:0007829|PDB:1T1T"
FT STRAND 9..11
FT /evidence="ECO:0007829|PDB:1T1T"
FT TURN 12..15
FT /evidence="ECO:0007829|PDB:1T1T"
FT STRAND 18..20
FT /evidence="ECO:0007829|PDB:1T1T"
FT HELIX 22..29
FT /evidence="ECO:0007829|PDB:1T1T"
FT STRAND 33..37
FT /evidence="ECO:0007829|PDB:1T1T"
FT TURN 39..41
FT /evidence="ECO:0007829|PDB:1T1T"
FT STRAND 44..49
FT /evidence="ECO:0007829|PDB:1T1T"
SQ SEQUENCE 63 AA; 7394 MW; 870B1E47F2DF991C CRC64;
KIDGYPVDYW NCKRICWYNN KYCNDLCKGL KADSGYCWGW TLSCYCQGLP DNARIKRSGR
CRA
